EP3211205B1 - Fuel filter system - Google Patents

Description

technical field

The invention relates to a fuel filter system with a cleaning module for cleaning a media stream of a first medium contaminated with a second medium, as well as a filter element for a cleaning module and a filter system.

State of the art

In the fuel system of an internal combustion engine, particularly of a motor vehicle, water can accumulate, for example due to the formation of condensation. For the engine to run reliably, the water content in the fuel must be separated. Known fuel systems have a water separator for this purpose, in which a water content is separated from the fuel using, for example, a coalescer or a hydrophobic filter medium.

The separation of the water component using known devices results in the separated water not being pure but containing fuel components. The disposal of the separated water contaminated with fuel components is problematic, particularly with regard to the required environmental protection.

From the DE 10 2004 036 070 A1 A water separator of a fuel system for an internal combustion engine is known, in which an adsorption filter is arranged downstream of its water outlet for adsorbing a fuel portion in the separated water. A filter element of the adsorption filter causes adsorption of the fuel portion with a retention behavior, whereby the fuel portion of the supplied separated water quantity accumulates on the filter material and is held there. The quantity of water passed through the adsorption filter has a high degree of purification downstream of the filter. The adsorption material of the filter element is, for example, activated carbon or a swellable, absorbent plastic such as polypropylene, polyethylene or PVC. The adsorption material is designed as a loose, granulate-like fill, as a sintered body or as a foam to form the filter element.

disclosure of the invention

An object of the invention is to provide a fuel filter system with a cleaning module for cleaning a media stream of a first medium contaminated with a second medium, which is designed to be easy to maintain.

The above object is achieved according to one aspect of the invention in a fuel filter system in that the fuel filter system has a cleaning module that comprises a housing with an inlet and an outlet and a replaceable filter element arranged in the housing, wherein the filter element has an absorbable and/or adsorbable material for absorbing at least a portion of the second medium in the first medium.

Favorable embodiments and advantages of the invention emerge from the further claims, the description and the drawing.

A fuel filter system with a cleaning module for cleaning a media stream of a first medium contaminated with a second medium is proposed, which comprises a housing with an inlet and an outlet and a replaceable filter element arranged in the housing. In this case, a flow direction of the media stream through the filter element is directed against gravity when installed as intended. The filter element has an absorbable and/or adsorbable material for absorbing at least a portion of the second medium in the first medium.

The cleaning module is used in a fuel supply system of a motor vehicle in which the first medium is separated water that is contaminated with the fuel as the second medium.

The water is produced when fuel, preferably diesel fuel, is cleaned using a diesel-water separator and the water is separated in the process. The water is usually collected in a collecting chamber that can be located directly in the filter housing. The water can also be collected in a separate container or a transparent bowl. The water is then drained from the filter system. If the water is to be drained into the environment, it is cleaned of remaining hydrocarbons before it comes into contact with the environment. Activated carbon is usually used for this purpose.

If activated carbon is to be used to clean water from the fuel supply systems of motor vehicles or stationary engines, the service life of the activated carbon adsorbent depends on the amount of water and the concentration of hydrocarbons in it. The higher the proportion of hydrocarbons or the higher the amount of water, the sooner the adsorbent is exhausted and must be replaced. The hydrocarbons, especially diesel, can partially dissolve in the water or also be present as an emulsion. The solubility observed in the field is between 3 and 6 mg hydrocarbons according to DIN EN ISO 9377-2 H 53. In most cases, however, a diesel-in-water emulsion is present, i.e. very fine diesel droplets are dispersed in the water. These emulsions are usually very stable, so they do not separate into two phases in the time available until the water is drained. The concentration of hydrocarbons in these emulsions can be between 500 mg/l and over 2000 mg/l of water according to DIN EN ISO 9377-2 H 53.

If activated carbon is to be used for adsorption, it is impossible to predict for every vehicle in every region worldwide how much water with which concentration of hydrocarbons will be produced. The regional (different markets with different fuel qualities) and local (different petrol station operators) differences are too great for a fixed amount of activated carbon to achieve a uniform service life, e.g. in the form of a lifetime component. The required amount of activated carbon would not be practical because the installation space in modern vehicles is very limited. Several liters of activated carbon could be necessary for a lifetime component if the fuel contains a relatively high amount of water and it is assumed that there is almost exclusively a diesel-in-water emulsion. The latter can be considered a given based on the industry's many years of experience with diesel-water separators.

Activated carbon can preferably be arranged in a filter element of a cleaning module, for example in the form of a cartridge, which can preferably be removed from the housing and replaced without tools, e.g. via a quick-release fastener. The shape of the cartridge is optimized for optimal use of the volume.

By designing it as a service part instead of a spare part, it is easier for the operator to replace the activated carbon. Furthermore, the amount of activated carbon can be significantly reduced compared to the design as a lifetime component. This saves installation space. Furthermore, the replacement interval can be flexibly adjusted based on regional and local differences in the amount of separated water. The loading of the activated carbon with hydrocarbons can be monitored by detecting the drainage processes in the vehicle. If a certain number of water drainage processes is exceeded, a message can be stored in the vehicle's error memory, for example. The activated carbon cartridge can then be replaced at the next regular service. An appropriate reserve must be calculated for this. If the operator of the engine uses water-free fuel, the activated carbon is not loaded and does not have to be replaced. The operator therefore incurs no additional costs compared to a lifetime component.

A ratio of length to diameter of the filter element of the cleaning module can, for example, be between 1:1 and 15:1, preferably the ratio can be between 2:1 and 6:1. In this way, a favorable flow through the absorbable and/or adsorbable material as well as an advantageous utilization of the capacity of the absorbable and/or adsorbable material can be achieved.

When installed as intended, the outlet can be conveniently located above the inlet or the entrance to the absorber and/or adsorbent or the separator of the filter element. The water can thus advantageously flow through the filter medium in the form of the absorbable and/or adsorbent material from bottom to top, whereby the pressure of the water can be just sufficient to be able to flow out of the cleaning module again via the outlet in the upper area of the filter element. The water can thus flow through the absorbable and/or adsorbent material, for example activated carbon, in a virtually pressure-free state and can thus be advantageously cleaned.

According to the invention, the housing comprises a first housing part and a second housing part, wherein the first and the second housing parts are designed to form a detachable, media-tight connection with one another. This means that the filter element can be arranged inside the housing and, after the two housing parts have been detached from one another, can be removed from the interior in order to be replaced or reconditioned if necessary. The fact that both housing parts are connected in a media-tight manner ensures that the medium to be cleaned can flow in through the inlet and only flow out again at the outlet.

According to the invention, the filter element is arranged on the second housing part, in particular arranged detachably. The filter element is connected to one of the two housing parts in such a way that it can be removed from the other of the two housing parts while hanging on the housing part, in order to be replaced or reconditioned after loading with the second medium, for example. This also ensures that the filter element can be handled conveniently by being able to pull it out of the other housing part with the housing part, without the filter element itself having to be touched. The seal between the two housing parts can be designed as a simple seal, since the media flow with low pressure in the cleaning module. The filter element can be permanently connected to the first or second housing part. However, it is also conceivable that the filter element is detachably connected.

According to the invention, the inlet is arranged on the first housing part and the outlet on the second housing part. For example, the first housing part can represent the lower housing part. The inlet is thus arranged on the lower housing part. The second housing part can be placed or screwed onto the first housing part from above. If the outlet is arranged on the second housing part in this way, the medium to be cleaned can flow through the cleaning module from bottom to top and flow out via the outlet on the upper housing part. This allows the filter element, which is arranged inside the two housing parts, to flow through and be cleaned from bottom to top. The filter element can also be conveniently removed upwards for replacement, so that as little leakage of the first medium as possible occurs when it is removed.

According to an advantageous embodiment, the inlet and the outlet can be arranged on the first housing part. In this way, both the inlet and the outlet can be arranged on the first housing part, which can be the lower of the two housing parts in the cleaning module. This makes it possible for the inlet and outlet to remain permanently connected to connection components and to remove the filter element, only the second housing part as the upper housing part has to be removed in order to replace or recondition the filter element. In this way, maintenance of the cleaning module is made very easy.

According to an advantageous embodiment, the adsorbable material can be provided as a loose, granular filling. A loose filling of individual grains in granular form is particularly advantageous for a medium to be cleaned to flow through. The loose, granular filling offers a particularly easy-to-flow embodiment in order to efficiently absorb and/or adsorb the medium to be absorbed. This enables both a very effective cleaning of the first medium from the second medium. In addition, this also ensures that the absorption capacity of the absorbable and/or adsorbable material is as economical as possible. is fully utilized, which advantageously enables a long service life of the filter element.

According to an advantageous embodiment, the absorbable and/or adsorbable material can be sintered and/or foamed. In alternative embodiments of the absorbable and/or adsorbable material, this can also be designed as a sintered body or foamed filter element. This also makes it possible for the absorbable and/or adsorbable material to offer the medium to be cleaned as large a surface as possible, so that the inner surface is highly accessible in the case of activated carbon, in order to combine effective cleaning with the greatest possible absorption capacity of the filter element, thereby extending the service life of the filter element. This results in high absorption or adsorption performance with low flow resistance.

According to an advantageous embodiment, the material capable of absorption and/or adsorption can comprise activated carbon. Activated carbon has proven to be a very suitable material, for example, for cleaning contaminated water from fuel such as diesel fuel by adsorbing the fuel. The grain size of the activated carbon can preferably be on average 0.5 mm. The mass of the activated carbon in the filter element can be, for example, 50 g to 400 g, preferably 100 g to 200 g.
According to an advantageous embodiment, the absorbable and/or adsorbable material can comprise a swellable plastic, in particular PE, PP or PVC, whereby a mixture of the materials mentioned is also possible. Likewise, other materials with similar, comparable properties can be used alternatively or additionally.

According to an advantageous embodiment, the absorbable and/or adsorbable material can comprise a bed of plastic tubes, in particular a bed of plastic tubes with a fleece. Such a bed of plastic tubes, in particular together with a fleece, also offers a large surface area in order to clean water contaminated with fuel as effectively as possible, for example, and also to achieve a long service life of the filter element by making favorable use of the absorption capacity of the absorbable and/or adsorbable material. Compared to activated carbon, the absorption capacity relative to the volume of the material is lower because the inner surface of activated carbon is superior to other materials.

According to an advantageous embodiment, an indicator can be provided to show that the filter element is loaded with the second medium. Such an indicator makes it possible to use the absorption capacity of the absorbable and/or adsorbable material as effectively as possible, so that the filter element only needs to be replaced or reconditioned when the absorption capacity is really exhausted and the service life of the filter element has been fully used up. In this way, it is possible to advantageously implement the principles of needs-based maintenance of a filter system.

According to a further aspect of the invention, a filter element is proposed which comprises an absorbable and/or adsorbable material for receiving a portion of a second medium in the first medium, wherein the filter element is designed and provided for receiving in a cleaning module according to one of the preceding claims. The filter element can contain the absorbable and/or adsorbable material in a suitable container through which the medium to be cleaned can flow, such as a porous casing or a fleece, which arrangement is particularly advantageous for a bed of absorbable and/or adsorbable material. Alternatively, it is also conceivable that the absorbable and/or adsorbable material is self-supporting, for example as a sintered or pressed body, so that the absorbable and/or adsorbable material can be arranged directly on one housing part and can be removed from the other housing part with this housing part or inserted into it.

According to an advantageous embodiment, the absorbable and/or adsorbable material can be provided as a loose, granular fill and/or sintered and/or foamed.

According to an advantageous embodiment, the absorbable and/or adsorbable material can comprise activated carbon and/or a swellable plastic, in particular PE, PP or PVC. Other materials with similar, comparable properties can also be used alternatively or in addition.

According to the invention, a fuel filter system is proposed for filtering a media flow comprising a first and a second medium. The filter system comprises a separating device for the first medium arranged in a filter system housing, as well as a cleaning module for absorbing and/or adsorbing a portion of the second medium in the separated first medium. The cleaning module comprises a housing with an inlet and an outlet and a replaceable filter element arranged in the housing. In this case, a flow direction of the media flow through the filter element is directed against gravity when installed as intended. The filter element has an absorbing and/or adsorbing material for absorbing at least a portion of the second medium in the first medium. The filter system is intended for separating the first medium, for example water, from the fuel, in particular diesel fuel. Since the separated water can contain small amounts of fuel, the separated water must be cleaned before it can be discharged into the environment. This cleaning can be carried out effectively with the help of the cleaning module described and under advantageous conditions such as compact construction and low maintenance. Since the cleaning module does not have to be designed for the service life of the filter system, since the filter element of the cleaning module can be replaced, it is possible to implement the cleaning module in the smallest possible installation space. This makes such a filter system advantageous both for reasons of installation space and from a cost perspective. The cleaning module can be arranged next to the filter system housing in one design or below the filter system housing in another design.

According to the invention, the cleaning module is designed as a cartridge and is detachably connected to the filter system housing with its first housing part and/or its second housing part. The cleaning module can thus be exchanged as a cartridge once it has been loaded with the second medium to be removed and/or adsorbed. This enables quick and cost-effective maintenance of the cleaning module. If the cleaning module is detachably connected to the filter system housing, the transfer of the first medium to be cleaned from the filter system housing to the cleaning module can also be carried out in an effective, media-tight manner. This also makes it possible to create the most compact possible structure of the filter system with cleaning module. The seal between the cleaning module and the filter system housing can be designed as a relatively simple seal, since the media flow flows from the filter system into the cleaning module under low pressure, whereby the pressure only has to be sufficient for the cleaned first medium to flow out again at the outlet of the cleaning module.

According to an advantageous embodiment, the cleaning module can be arranged in the filter system housing. This alternative arrangement of the cleaning module in the filter system housing enables a particularly compact structure of the entire filter system with integrated cleaning module, which enables favorable solutions for the processing of the separated first medium both in terms of installation space requirements and from a cost perspective.

According to an advantageous embodiment, the filter system can be designed as a fuel filter system and the cleaning module can be provided for absorbing and/or adsorbing a fuel component in separated water.

Short description of the drawings

Further advantages emerge from the following description of the drawings. The drawings show embodiments of the invention. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

Examples include:

Fig. 1

a schematic representation of a filter system in side view with a cleaning module according to an embodiment of the invention;

Fig. 2

the filter system with cleaning module Fig. 1 in plan view;

Fig. 3

the filter system with cleaning module Fig. 1 with the filter element of the cleaning module removed;

Fig. 4

a schematic representation of a filter system with a cleaning module according to a further embodiment of the invention, in which the entire cleaning module is designed to be removable;

Fig. 5

a schematic representation of a filter system in side view with a cleaning module according to a further embodiment of the invention, in which the cleaning module is arranged on the underside of the filter system housing;

Fig. 6

the removed cleaning module after Fig. 5 ;

Fig. 7

the filter element of the cleaning module after Fig. 6 in longitudinal section; and

Fig. 8

the filter element of the cleaning module after Fig. 6 in top view.

embodiments of the invention

In the figures, identical or similar components are numbered with identical reference symbols. The figures merely show examples and are not to be understood as limiting.

The invention is described with reference to a cleaning module 10 for cleaning a media flow of a first medium contaminated with a second medium for a filter system 100, wherein the filter system 100 is, by way of example, a preferred fuel filter system and the first medium is water and the second medium is diesel fuel, wherein the water is separated from the diesel fuel in the filter system 100. However, other areas of application of the filter system 100 are also conceivable.

Figure 1 shows a schematic representation of a filter system 100 in side view with a cleaning module 10 according to an embodiment of the invention. The filter system 100 for filtering the media flow comprising the first and second medium has a separation device for the first medium, not shown, arranged in the filter system housing 102. The filter system housing 102 has a preferably detachable, media-tight cover 104 in order to maintain or replace a filter element inside the filter system housing 102, also not shown. The filter system 100 also has the cleaning module 10 for absorbing and/or adsorbing a portion of the second medium in the separated first medium, which is connected to the filter system housing 102 via a connecting part 106. The cleaning module 10 has a housing 12 with an inlet 18 and an outlet 20, wherein the inlet 18 is arranged on the first housing part 14 and the outlet 20 is arranged on the second housing part 16. The first and second housing parts 14, 16 are designed to form a, in particular detachable, media-tight connection to one another. The two housing parts 14, 16 can be screwed together or connected with a quick-release fastener, for example. Alternatively, an outlet 21 is shown, which can be arranged on the first housing part 14. Such a solution is also advantageous, since the second housing part 16 can then be removed, for example to remove the filter element 30, without breaking a connection from the outlet 21 to further components.

The replaceable filter element 30 is detachably arranged in the housing 12. The filter element 30 has an absorbable and/or adsorbable material 34 for absorbing at least a portion of the second medium in the first medium. The absorbable and/or adsorbable material 34 can preferably comprise activated carbon. Alternatively, it is also conceivable that the absorbable and/or adsorbable material 34 comprises a swellable plastic, in particular PE, PP or PVC, which can also be designed as a bed of plastic tubes, in particular as a bed of plastic tubes with a fleece. The absorbable and/or adsorbable material 34 can be provided as a loose, granular bed and/or provided sintered and/or provided foamed.

The flow direction 32 of the media flow is from the filter system housing 102 through the connecting part 106 through the inlet 18 into the housing 12 of the cleaning module 10, where the media flow through the filter element 30 in the intended installed state is directed against gravity and leaves the cleaning module 10 via the outlet 20 or, in the alternative embodiment, via the outlet 21 at the top.

In addition, an indicator for displaying a load with the second medium can be arranged on the cleaning module 10 in order to enable demand-oriented maintenance.

In Figure 2 The filter system 100 with cleaning module 10 is made of Figure 1 shown in plan view. The filter system housing 102 can be seen from above with the cover 104. The cleaning module 10 is arranged on the connecting part 106 connected to the filter system housing 102. From above, the second housing part 16 can be seen on the connecting part 106. The outlet 20 is omitted from the illustration.

Figure 3 shows the filter system 100 with cleaning module 10 from Figure 1 with the filter element 30 of the cleaning module 10 removed. The filter element 30 with the absorbable and/or adsorbable material 34 is arranged on the second housing part 16 in this exemplary embodiment. The filter element 30 can be permanently connected to the second housing part 16 and thus treated as a unit. However, it is also conceivable that the filter element 30 is detachably arranged on the second housing part 16 and can be removed therefrom and replaced separately. The filter element 30 with the second housing part 16 can thus be removed upwards from the first housing part 14 in the form of a cartridge in order to be replaced or reconditioned, for example. A new filter element 30 with a second housing part 16 can be reinserted and connected to the first housing part 14 in a media-tight manner, for example screwed or clipped, in order to put the cleaning module 10 back into an operational state. The advantage of such an embodiment is that when the filter element 30 is removed with the second housing part 16, the remaining first medium remains in the first housing part 14 and the environment is thus not contaminated.

Figure 4 shows a schematic representation of a filter system 100 with a Cleaning module 10 according to a further embodiment of the invention, in which the entire cleaning module 10 is designed to be removable. In this embodiment, the cleaning module 10 is designed as a cartridge and is detachably connected to the filter system housing 102 with its first housing part 14. For maintenance purposes, the entire cleaning module 10 can be removed upwards from the connecting part 106 and a new or reconditioned cleaning module 10 can be placed back on the connecting part 106 in order to put the filter system 100 back into an operational state.

Alternatively, it is also conceivable that the cleaning module 10 is arranged directly in the filter system housing 102 so that it can be removed from the filter system housing 102 and reinserted for maintenance purposes.

Figure 5 shows a schematic representation of a filter system 100 in side view with a cleaning module 10 according to a further embodiment of the invention, in which the cleaning module 10 is arranged on the underside of the filter system housing 102. The cleaning module 10 is connected to the underside of the filter system housing 102 in a media-tight manner. The media flow is introduced from above through the middle of the cleaning module 10. The filter element 30 of this embodiment is in Figure 7 and is designed as a hollow cylinder made of absorbable and/or adsorbable material 34, so that the media flow can flow downwards in the central cavity 40 of the filter element 30 and then flow upwards in the jacket of the hollow cylinder through the absorbable and/or adsorbable material 34. For this purpose, the outside of the cavity 40 is expediently designed to be media-tight, for example by the second housing part 16 designed as a hollow cylinder, which then lines the cavity 40 in order to guide the media flow downwards through the cavity 40, so that the media flow flows through the absorbable and/or adsorbable material 34 only in the jacket of the hollow cylinder from bottom to top and does not pass directly from the cavity 40 into the absorbable and/or adsorbable material 34. After flowing through the filter element 30, the cleaned first medium is then discharged to the outside via the outlet 20 arranged at the upper edge of the cleaning module 10.

Figure 6 shows the removed cleaning module 10 after Figure 5 . Inlet 18 is at the top of the housing 12 of the cleaning module 10. The housing 12 itself can be cylindrical, for example.

In Figure 7 the filter element 30 of the cleaning module 10 is Figure 6 shown in longitudinal section. The filter element 30 has a hollow cylindrical body made of absorbable and/or adsorbable material 34 with a central cavity 40. The cavity 40 with its upper opening represents the inlet 18 of the cleaning module 10. The second housing part 16 of the housing of the cleaning module can be designed, for example, as a hollow cylinder, by means of which the cavity 40 can be sealed on its outside in a media-tight manner in order to prevent the media flow from entering the cleaning module 10 through the cavity 40 directly into the absorbable and/or adsorbable material 34 of the filter element 30. The media flow can thus flow out from the bottom of the second housing part 16 and thus enter the absorbable and/or adsorbable material 34 of the filter element 30 from below in order to flow through the absorbable and/or adsorbable material 34 of the filter element 30 from bottom to top and thus ensure effective cleaning of the first medium by absorbing or adsorbing the portion of the second medium in the material 34.

Figure 8 shows the filter element 30 of the cleaning module 10 Figure 6 in plan view. The cavity 40 is shown with the inlet 18 as the central opening of the filter element 30.

Claims (9)

1. A fuel filter system (100) for filtering a media flow comprising water and fuel, having a separating device for water disposed in a filter system housing (102), and a cleaning module (10) for absorptively and/or adsorptively receiving a fuel portion in the separated water, wherein the cleaning module (10) comprises a housing (12) having an inlet (18) and an outlet (20, 21) and a replaceable filter element (30) disposed in the housing (12), wherein the filter element (30) features a material (34) capable of absorption and/or adsorption for accommodating at least some of the fuel in the separated water, characterized in that the cleaning module (10) is disposed beside the filter system housing (102), in that the housing (12) comprises a lower first housing component (14) and an upper second housing component (16), wherein the inlet (18) is disposed on the first housing component (14), wherein the first and the second housing components (14, 16) are designed for being detachably interconnected in a media-tight manner, and wherein the filter element (30) is disposed on the second housing component (16) and forms a cartridge with it, and in that a flow direction (32) of the media flow through the filter element (30) in the installed state as intended is directed against the force of gravity.
2. The fuel filter system according to claim 1, wherein the filter element (30) is disposed detachably on the second housing component (16).
3. The fuel filter system according to claim 1 or 2, wherein the cleaning module (10) is detachably connected to the filter system housing (102) with its first housing component (14) and/or its second housing component (16).
4. The fuel filter system according to one of the preceding claims, wherein the material (34) capable of absorption and/or adsorption is provided as a loose, granular bed.
5. The fuel filter system according to one of the preceding claims, wherein the material (34) capable of absorption and/or adsorption is provided in sintered and/or foamed form.
6. The fuel filter system according to one of the preceding claims, wherein the material (34) capable of absorption and/or adsorption features activated carbon.
7. The fuel filter system according to one of the preceding claims, wherein the material (34) capable of absorption and/or adsorption features a plastic material capable of swelling, in particular PE, PP or PVC.
8. The fuel filter system according to claim 7, wherein the material (34) capable of absorption and/or adsorption features a bed comprising plastic tubes, in particular features a bed comprising plastic tubes having a non-woven fabric.
9. The fuel filter system according to one of the preceding claims, wherein an indicator for indicating a loading of the filter element (30) with the second medium is provided.

Images